Charging Rates

[AZBill]

Helpful info. Thanks!
Doesn't 920v rating indicate around 460v nominal for the battery modules in the enclosure? I know in LVB world.....in order to charge a 12v system you need (prefer) around 14v so I presume it's similar for HVB. Charging an EV with 400v nominal battery would require 10-15% more voltage (in theory anyway...)

Am I close?

Some vehicles are using ~400V nominal, I think Tesla is that, so full charge is 450V. The Bolt is 360V nominal, 400V at full charge. I think the Mach E is roughly the same as the Bolt.

I am not 100% sure, but I believe the Taycan is 900V at full charge and about 800V nominal.

Generally speaking the charge rate at low SoC will be with the nominal voltage, thus you will not see 400V until late in the charging cycle, after the taper. I hear people moan all the time about chargers not outputting their KW rating. It is because of the current limit.

A battery with a 360V nominal, charging on a 150KW ABB unit with 350A limit, will only get 126KW maximum.

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[GoGoGadgetMachE]

The 2 year old Wiggins eBull 36,000 lb capacity forklift also requires 800V charging (not available for public roads, though!). I convinced ChargePoint to move up their CPE-250 1000V charger development about 3 years ago, since Wiggins was delivering 18 units to the Port of Stockton and ABB was the only company offering 800V DCFC capabilities back then in the olden days (2018), and they had 6+ month lead times. ChargePoint came through in time. First unit was placed in service late 2019. Lots of truck and vehicle companies are following my lead now! LOL! The right side of the forklift used to be a diesel fuel tank, now has 2 of the 4 large battery boxes on board behind that sheet metal. The other two are in the center behind the operator. Each battery box weighs over 600 lbs.

but how fast will it get to on a track straightaway, and how will the speed curve look getting there? ??

 

[BMT1071]

but how fast will it get to on a track straightaway, and how will the speed curve look getting there? ??

Not as fast as a 2.0T I'll bet ya. ? ?

 

[AZBill]

The EA out by 101 and Camelback has the capability to charge 800v EVs. I think it's just one of the dispenser units though. That one in the back, right hand side I think.
I think the way it works is the amps are about the same but since the voltage is higher than it can deliver more kW to the vehicle.

There are battery modules for each dispenser unit. They are located behind the enclosure. As best as I can tell, the battery modules are all 460 nominal units so in order to charge an 800V vehicle they need to pair two modules together. Not sure how they accomplish that exactly. There must be some massive contactors inside those modules stored inside the enclosure.

Standard transformer into those units is 480V AC. They rectify it to DC, then step it up to the necessary voltage. Those gray boxes are the power converters, not batteries.

I have charged at those units. They are all rated the same, 150KW output at those.

The units at the Walmart in Buckeye, I-10 and Watson Road, just got Tesla batteries installed, those are in addition to the power converter boxes. They have the older ABB units, two 350KW and two 150KW.

 

[Sam2084]

Everyone is behind Hyundai’s new E-GMP architecture. It’s an 800v system, so can charge much faster than any 400v system.

System voltage doesn’t have nearly the effect on charging rate as people think. Battery cells can only charge so fast. Putting more in series won’t change that. Higher voltage can raise the ceiling on charge rate if you’re limited on current, but the gate is almost always the C rate of the battery cells. Hyundai’s new charge technology is better for reasons other than system voltage.

 

[SnBGC]

Standard transformer into those units is 480V AC. They rectify it to DC, then step it up to the necessary voltage. Those gray boxes are the power converters, not batteries.

I have charged at those units. They are all rated the same, 150KW output at those.

The units at the Walmart in Buckeye, I-10 and Watson Road, just got Tesla batteries installed, those are in addition to the power converter boxes. They have the older ABB units, two 350KW and two 150KW.

Interesting. Thought for sure those were power storage of some kind. Demand charges must be crazy there. All the DCFC devices that we have experienxe with contain energy storage devices to smooth the peak demand down to a manageable level. Those seem awfully large for transformer but then again....it's 500A so that isn't anything to sneeze at.

 

[AZBill]

System voltage doesn’t have nearly the effect on charging rate as people think. Battery cells can only charge so fast. Putting more in series won’t change that. Higher voltage can raise the ceiling on charge rate if you’re limited on current, but the gate is almost always the C rate of the battery cells. Hyundai’s new charge technology is better for reasons other than system voltage.

The current can be lowered significantly, that is why 800V is better. Smaller wire size and not running up against the 500A current limit is the real issue. It is the current rating of the wires and contactors outside of the battery that work better with less current. None of the current 400V cars can exceed 200 kw charging, no matter how big the battery is. Hummer has a 200 KWH battery and the only way they can achieve the 350 kw charge rate is to go to 800V.

 

[engnrng]

The current can be lowered significantly, that is why 800V is better. Smaller wire size and not running up against the 500A current limit is the real issue. It is the current rating of the wires and contactors outside of the battery that work better with less current. None of the current 400V cars can exceed 200 kw charging, no matter how big the battery is. Hummer has a 200 KWH battery and the only way they can achieve the 350 kw charge rate is to go to 800V.

@AZBill is spot on with his comments about current, voltage, and charge rate. Our battery systems don't taper down much until 90% State of Charge, but it is due to limiting the charge rate to 0.85C or less until then. We have 100 kWH aboard, but the systems engineers limit the charge rate to retain longevity of capacity. Max charge rate is 85 kW on our system. So, a recharge from 10% to 90% takes about an hour (if you have a charger that can deliver 90+ kW). The batteries are expected to retain 80% of original capacity after 2500 to 3000 charge cycles - about 15 years for our forklifts. Warranty is for 70% at 7 years.

 

[mjschillingtec]

That is a good home level 2 charging rate. I put in the chargepoint home flex with 60 amp breaker and getting slightly above 30 miles in an hour of charging.

I also put in a ChargePoint Flex on a 60a circuit and I charged for the first time this w/e and only got about 11-12 miles per hour overnight. Does anyone know where I should start my troubleshooting? I did have the circuit installed by a certified electrician that I have worked with for years.

 

[Texas-E]

I also put in a ChargePoint Flex on a 60a circuit and I charged for the first time this w/e and only got about 11-12 miles per hour overnight. Does anyone know where I should start my troubleshooting? I did have the circuit installed by a certified electrician that I have worked with for years.

I have a ChargePoint at 60A, too. Did you configure it within the app? You can access it from the Menu-Home Charger-Settings. Pick Hardwired and 60A for your breaker. I do not doubt you or your electrician, but go look at the breaker to make sure it is 60A just to be safe.

 

[Maquis]

Pick Hardwired and 60A for your breaker. I do not doubt you or your electrician, but go look at the breaker to make sure it is 60A just to be safe.

I agree - check the setting. The breaker size will itself not affect charging rate (unless it trips!).

 

[mjschillingtec]

I have a ChargePoint at 60A, too. Did you configure it within the app? You can access it from the Menu-Home Charger-Settings. Pick Hardwired and 60A for your breaker. I do not doubt you or your electrician, but go look at the breaker to make sure it is 60A just to be safe.

Thanks - I did check the breaker. I can only configure up to 50a in the app since I am a plug in.

 

[Texas-E]

Thanks - I did check the breaker. I can only configure up to 50a in the app since I am a plug in.

Yes, to get the max, it has to be hardwired. Hopefully, your electrician ran the appropriate gauge wire to the outlet. If not, I'm not sure I would be comfortable with a 60A breaker on 50A wiring and plug.

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